The present invention relates to rotary positive blowers and more particularly to a noise reduction system for a rotary positive blower that may be employed in a carpet cleaning system as well as other systems employing rotary positive blowers.
Van mounted steam carpet cleaning machines are known in the art that have parallel high frequency silencers with low back pressure. The outputs of these high frequency silencers are exhausted through two holes cut in the van floor. The two silencers do a sufficient job of suppressing high frequency sounds with very strong low frequency noise exiting out through the van floor. This strong low frequency noise was found to be excessive and at times very embarrassing. Frequently, customers and their neighbors would register strong complaints about the "sound assault" which so dramatically affected the quality of life as the carpets were cleaned in a customer's home. More than once, surrounding homes literally would shake as powerful, low frequency shock waves generated by the large blower reverberated throughout the neighborhoods.
In an attempt to reduce this low frequency noise, the inventive noise reduction system of the present invention was discovered and pleasantly reduced the low frequency noise and included other advantages to the entire carpet cleaning system.
An object of the present invention is to provide a noise reduction system for a rotary positive blower.